Taking Feynman integrals as the generalized hypergeometric functions [1]},
one finds that the \(D-\) module of a Feynman diagram [2]} is isomorphic to
Gel'fand-Kapranov-Zelevinsky (GKZ) \(D-\) module [3]}, [4]}, [5]}, [6]}, [7]}.
Correspondingly Feynman integrals satisfy the systems of
holonomic linear partial differential equations (PDEs) [8]} whose singularities
are determined by the Landau singularities.
